不要序列化（xml）特定的枚举值

Question

我的节目：

using System;
using System.IO;
using System.Xml;
using System.Xml.Serialization;

namespace Test
{
    public enum TestEnum
    {
        [XmlEnum(null)]
        Nothing,
        [XmlEnum("A")]
        A,
        [XmlEnum("B")]
        B
    }

    public class TestClass
    {
        [XmlAttribute("firstName")]
        public string Name { get; set; }
        [XmlAttribute("testEnum")]
        public TestEnum TestEnum { get; set; }
    }

    class Program
    {
        static void Main(string[] args)
        {
            TestClass testClass1 = new TestClass() { Name = "TestClass1", TestEnum = TestEnum.A };
            XmlSerializer serializer1 = new XmlSerializer(typeof(TestClass));
            StringWriter stringWriter1 = new StringWriter();
            serializer1.Serialize(stringWriter1, testClass1);
            Console.WriteLine(stringWriter1.ToString());

            Console.WriteLine();

            TestClass testClass2 = new TestClass() { Name = "TestClass2", TestEnum = TestEnum.Nothing };
            XmlSerializer serializer2 = new XmlSerializer(typeof(TestClass));
            StringWriter stringWriter2 = new StringWriter();
            serializer2.Serialize(stringWriter2, testClass2);
            Console.WriteLine(stringWriter2.ToString());
        }
    }
}

提供以下输出：

<?xml version="1.0" encoding="utf-16"?>
<TestClass xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xmlns:xsd="http://www.w3.org/2001/XMLSchema" 
firstName="TestClass1" testEnum="A" />

<?xml version="1.0" encoding="utf-16"?>
<TestClass xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xsd="http://www.w3.org/2001/XMLSchema" 
firstName="TestClass2" testEnum="Nothing" />

但是在Enum Value“Nothing”的情况下，我想要以下输出（一直删除属性和值）：

<?xml version="1.0" encoding="utf-16"?>
<TestClass xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xsd="http://www.w3.org/2001/XMLSchema" 
firstName="TestClass2" />

我该怎么做？ [XmlIgnore]对特定的枚举值不起作用。